Josh Fox, a liberal environmental activist, finds himself at odds with President Barack Obama. Phelim McAleer, a free-market conservative, is echoing the Democratic president’s support for natural gas.

The two don’t see eye-to-eye on much of anything, especially each other.

“He’s a very skillful filmmaker,” McAleer said of Fox. “He’s one of the most trusted scientists in America at the moment, even though he has zero qualifications. I don’t accept that, but a lot of Americans do.”

Fox, in an email to The Associated Press, said McAleer “is not a credible source of information” and is “a climate change denier.”

Their dueling documentaries — the sequel to Fox’s Oscar-nominated “Gasland” aired July 8 on HBO and McAleer’s “FrackNation” aired the following night on AXS — have clear aims when it comes to hydraulic fracturing, or fracking, the gas drilling method by which chemical-laced fluid is injected into the earth to free natural gas trapped deep underground.

Experts say the pro- and anti-drilling movements represented by the filmmakers each have some good points — even though Fox claims the process is an environmental and public health disaster while McAleer says Fox distorts facts and ignores the benefits of drilling.

Jeff Frankel, an economics professor at Harvard’s Kennedy School of Government, said, “The fracking revolution is clearly good news from the national security and economic standpoint” since it reduces imports and generates jobs and investment in America. He said the most extreme fracking critics don’t seem to understand how much the gas boom is reducing pollution by cutting the amount of coal that gets burned in power plants.

Yet the fracking critics have legitimate concerns, Frankel said. It makes sense that they would want to be cautious about drilling in some areas such as sensitive watersheds. Residents should get to choose whether they want drilling locally, he said.

If all the anti-drillers’ passion “gets channeled into vigilant regulation, then it will turn out to have been a good thing,” Frankel said.

McAleer concedes that Fox appears to be swaying people in at least some states to oppose drilling.

McAleer thinks opponents have a very strong chance of banning fracking in New York, and a good chance of winning in places like Colorado and California. But he added that there’s an irony to that.

New York has placed a moratorium on fracking, but natural gas is the top source of energy for the state, dwarfing hydroelectric or nuclear power. New York gets virtually all that natural gas from states that allow drilling, such as Pennsylvania.

Environmental groups in Colorado and California have also tried to limit or ban fracking, even though those states have long histories of oil and gas drilling.

“If you want to ban fracking, that’s your business. But you’re just shifting production to the next state,” McAleer said.

Fox said, “New Yorkers are becoming increasingly aware that if they want to ban fracking they have to begin to change their energy infrastructure to renewable energy,” and that more and more groups are pushing for that transition.

But even prominent scientists who warn about the dangers of global warming say the switch will take a long time.

“Suggesting that renewables will let us phase rapidly off fossil fuels in the United States, China, India or the world as a whole is almost the equivalent of believing in the Easter Bunny and Tooth Fairy,” former NASA scientist James Hansen wrote in an online essay in 2011.

Hansen added that “renewable energies are grossly inadequate for our energy needs now and in the foreseeable future.”

That’s essentially why the Obama administration supports using natural gas as a “bridge” fuel during the transition to renewables, since gas emits half the carbon dioxide of coal.

Fox plans to keep hammering away at fracking. He’s working on a short documentary on illnesses affecting gas workers and plans eventually to move onto projects on the broader issues of climate and sustainability.